This application claims the priority of Korean Patent Application No. 2003-3668, filed on Jan. 20, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a biomolecular detection apparatus, and more particularly, to an automated fluidic system for detecting protein in a biological sample.
2. Description of the Related Art
Most diagnostic methods involve a main step of detecting whether a particular protein exists in a biological sample. Various diagnostic methods, such as enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), fluorometry, nuclear magnetic resonance spectroscopy, and calorimetric assay, have been widely used, with the ELISA method being the most common.
There are three technologies involved in detecting a particular protein by ELISA: an antigen-antibody chemical reaction technology, in which an antibody that can be immobilized on a substrate or can be labeled with an enzyme is reacted with a protein of interest; an optical detection technique, in which a color variation in the substrate caused by the reaction with the enzyme is optically measured; and a fluid handling technology, in which various fluids are supplied to a multi-well plate in a predetermined order and the multi-well plate is washed between the steps of supplying the various fluids.
The fluid handling technology requires elaborate manipulations by a skilled operator for each step, for example, pipetting fluid into the multi-well plate and flushing the fluid, and takes much time. Therefore, an automated fluid manipulation process to allow for easier protein detection and to reduce the time required for detection is required.
To meet this requirement, various automated systems for manipulating and assaying components in each reservoir when detecting protein using a multi-well plate have been developed.
Korean Laid-open Patent Publication No. 2003-435543 discloses a micro-fluidic control system that includes a series of channels that allow a very small fraction of fluid to pass.
Korean Laid-open Patent Publication No. 2002-71853 discloses a system and method for detecting and identifying various molecular events in a test sample. The system includes fluid storage reservoirs, a signal supply unit that transmits an input test signal, a detecting probe, and a signal detection unit.
U.S. Pat. No. 6,033,911 discloses an automated assaying device that includes a plurality of controllable lumens arranged to form clusters, which are separately controlled according to sample inflow and outflow. This automated assaying device includes a unique washing system capable of washing the entire assaying system.
However, a series of assaying processes, including sample injection, channel washing, dye injection, channel washing, and sample detection, cannot be fully automated with the above-described conventional automated assay devices. In addition, the conventional automated assay systems require a separate power source and a skilled operator due to their structural complexity, for maintenance and repair as well as operation. Further, the conventional automated assay systems are expensive and uneconomical.